Effect of liraglutide on physical performance in type 2 diabetes (LIPER2): A randomised, double-blind, controlled trial

Glucagon-Like Peptide-1 Receptor Agonists and Sodium Glucose Cotransporter-2 Inhibitors and Cardiorespiratory Fitness Interaction

INTRODUCTION

Cardiorespiratory fitness (CRF) is a stronger predictor of mortality than traditional risk factors and is a neglected vital sign of health. Enhanced fitness is a cornerstone in diabetes management and is most often delivered concurrently with pharmacological agents, which can have an opposing impact, as has been reported with metformin. Considering the rapid evolution of diabetes medications with improved cardiovascular outcomes, such as glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors, it is of importance to consider the influence of these vis-a-vis effects on CRF.

MATERIALS AND METHODS

Combining the words glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors with cardiorespiratory fitness, an online search was done using PubMed, Embase, Scopus, Web of Science, Scientific Electronic Library Online, and Cochrane.

RESULTS

There were only a few randomized controlled studies that included CRF, and the results were mostly neutral. A handful of smaller studies detected improved CRF using sodium glucose cotransporter-2 inhibitors in patients with congestive heart failure.

CONCLUSIONS

Since CRF is a superior prognosticator for cardiovascular outcomes and both medications can cause lean muscle mass loss, the current review highlights the paucity of relevant interactive analysis.

Newer Diabetes Management Options and Physical Fitness to Promote Cardiovascular Benefits

A plethora of diabetes studies and established clinical guidelines show the strong salutary benefit of aerobic, resistance, and/or combination exercise for improved glycemic and cardiovascular outcomes. Promotion of physical fitness is a cornerstone approach to improved diabetes management especially since subjects with diabetes have reduced baseline aerobic exercise capacity (i.e., reduced cardiorespiratory fitness) with associated increased risk for premature all-cause and cardiovascular mortality. Since medications are often used in conjunction with fitness promotion this can result in complex interaction between management modalities. More recently, newer options such as glucose transporter-2 inhibitors and incretin agonists have shown to improve cardiovascular disease (CVD) outcomes in cardiovascular outcomes trials. Indeed, both classes of agents have experimentally the potential to synergize with exercise training but clinical data vis-à-vis cardiorespiratory fitness is still preliminary. Review of the interaction of exercise and metformin shows no improvement in cardiorespiratory fitness. The use of glucose transporter-2 inhibitors may improve fitness performance in those with diabetes and heart failure. Although incretin agonists have physiological effects on the vasculature and heart, they lack similar clinical supportive data.

Effects of glucose-lowering agents on cardiorespiratory fitness

Exercise therapy is essential for the management of type 2 diabetes (T2D). However, patients with T2D show lower physical activity and reduced cardiorespiratory fitness than healthy individuals. It would be ideal for clinicians to co-prescribe glucose-lowering agents that improve cardiorespiratory fitness or exercise capacity in conjunction with exercise therapy. Metformin does not improve cardiorespiratory fitness and may attenuate any beneficial effect of exercise in patients with T2D. In contrast, thiazolidinediones appear to improve cardiorespiratory fitness in patients with T2D. Although evidence is limited, sodium-glucose cotransporter 2 (SGLT2) inhibitors may improve cardiorespiratory fitness in patients with heart failure, and the effect of glucagon-like peptide-1 (GLP-1) receptor agonists on cardiorespiratory fitness is controversial. Recent clinical trials have shown that both SGLT2 inhibitors and GLP-1 receptor agonists exert a favorable effect on cardiovascular disease. It becomes more important to choose drugs that have beneficial effects on the cardiovascular system beyond glucose-lowering effects. Further studies are warranted to determine an ideal glucose-lowering agent combined with exercise therapy for the treatment of T2D.

Effect of liraglutide on physical performance in type 2 diabetes: Results of a randomized, double-blind, controlled trial (LIPER2)

AIMS

To assess the effect of the GLP-1 analogue liraglutide on measures of cardiac function and physical performance in patients with type 2 diabetes (T2D).

METHODS

In this phase-IV randomized double-blind placebo-controlled parallel-group clinical trial at a tertiary hospital, T2D patients with HbA_1c levels of 7-10% with oral agents and/or intermediate-/long-acting insulin were allocated (computer-generated randomization, ratio 1:1) to either liraglutide 1.8 mg/day or a placebo for 6 months. The primary endpoint was maximum oxygen consumption (VO_2max) during cycle ergometry, while other procedures included a 6-min walk test, echocardiography, anthropometry and blood tests. Safety endpoints were also monitored, and an intention-to-treat analysis was performed.

RESULTS

A total of 24 patients (15 women) aged 52 (11.7) years, with diabetes duration of 8.7 (5.8) years, BMI 34.98 (6.2) kg/m² and HbA_1c 8.2% (0.68%), were randomized to liraglutide 1.8 mg daily or placebo. There were no differences in VO_2max [17.98 (4.8) vs. 15.90 (4.96) mL/kg/min; P > 0.10], VE/VCO₂ slope [30.18 (4.8) vs. 32 (4.49)], left ventricular ejection fraction or 6-min walk test [530.7 (86) vs. 503.9 (84) m] at 6 months. HbA_1c was lower (6.7% vs. 7.7%; P =  0.005), with a trend towards lower maximum systolic blood pressure during ergometry [171.7 (24.4) vs. 192.5 (25.6); P = 0.052] in the liraglutide group at the end of the study. There were no severe adverse events.

CONCLUSION

In this trial, liraglutide improved glycaemic control in T2D, but had no significant effects on either physical performance or myocardial function.